Antiinflammatory Foods Mediate Link Between Body Fat and Pain

New findings reported in Pain suggest that the consumption of anti-inflammatory foods mediates the link between body fat and body pain in healthy adults.1

Substantial evidence shows a positive association between body weight and chronic pain throughout the lifespan, with pain levels increasing with higher levels of obesity.2 A recent longitudinal study determined that an elevated body mass index (BMI) led to low back pain but not vice versa, indicating that increased BMI may have a causal influence on pain symptoms.3

The present investigation sought to elucidate the mechanisms underlying this relationship. It has been proposed that obesity may lead to greater pain symptoms by increasing systemic inflammation.2 Noting earlier findings linking consumption of anti-inflammatory foods with reduced inflammatory markers (interleukin-6, C-reactive protein [CRP], and tumor necrosis factor-alpha), the researchers examined whether such a diet might play a role in the relationship between body fat and body pain.

For each participant (n=98; 60% women; age 20 to 78), the researchers conducted “food recall interviews,” and collected measures of body fat, height and weight, and scores on both the bodily pain subscale from the Medical Outcomes Study Short Form-36 and the Hospital Anxiety and Depression Scale. They then evaluated participants' dietary quality with the Healthy Eating Index-2010 (HEI-2010).

The analysis showed that scores on the HEI-2010 mediated the indirect association between BMI and body pain, assessed using the bindirect parameter (bindirect = −0.34; 95% CI, −0.68 to -0.13). This relationship remained significant after adjusting for arthritis and joint pain, age, the use of pain medications, psychological distress, and education level (bindirect = −0.20; 95% CI, −0.47 to −0.04). Further analysis of the different categories of food reflected in the HEI-2010 revealed that seafood and plant proteins were the only foods that mediated the BMI-body pain relationship (bindirect = −0.14; 95% CI, = −0.39 to −0.02).

The HEI-2010 “reflects consumption of foods with anti-inflammatory effects, thus we believe the diet contributes to reduced systemic inflammation which, in turn, leads to reduced body pain,” lead investigator Charles F. Emery, PhD, a professor of psychology and internal medicine at Ohio State University in Columbus, told Clinical Pain Advisor. Future research on dietary intake and pain should include blood markers of inflammation, and it would be worthwhile to evaluate the effects of an anti-inflammatory dietary intervention on pain outcomes.

Summary and Clinical Applicability

The current study found that dietary intake – particularly of anti-inflammatory foods – mediates the association between body weight and pain.

In terms of immediate clinical implications, these results point to the importance of diet quality in patients with pain disorders. “Although patients are often encouraged to lose weight through restriction of calories, these data would suggest that the quality of food ingested is an equally important consideration,” said Dr Emery.

Limitations

Limitations include the 2-item measure of pain used in the study, which does not capture chronic pain lasting longer than 4 weeks, as well as the self-report nature of the dietary information.